Insulin - description and photos

The performance-enhancing properties of insulin mean misuse of the hormone is becoming increasingly common in some sports. But health experts warn that those dabbling in the drug could cause themselves irreparable damage.

Almost the "perfect drug"

Recently, it emerged that a 31-year-old man was admitted to hospital in Yorkshire in a coma having taken too much insulin as part of a bodybuilding regime. Last year the 35-year-old holder of eight power-lifting titles in Scotland was in a coma for two months after suspected abuse of insulin.

Dr Rob Dawson is a GP who runs a confidential needle exchange scheme for bodybuilders and sportsmen. He says about 10 per cent of the 450 patients he regularly sees have said they use insulin.

Insulin is almost the perfect drug to increase stamina or endurance for athletes. It is readily available, cheap, difficult to detect and actually enhances performance. But it can be lethal.

"Insulin is bad for body builders.I cannot stress it enough. I would never ever use it," says 45-year-old Mick Hart, an expert on bodybuilding. He runs a bodybuilding magazine and has written the acclaimed book, "The Layman's Guide to Steroids". He says, "As an authority in the sport, it is the deadliest thing that has ever hit the sport."

Insulin info

Insulin is a natural hormone secreted from the pancreas, which controls the levels of glucose in the body. Diabetics need to inject it to prevent a rise in blood glucose. However if too much is injected and blood sugar falls to a very low level then this can lead to sweating, shaking and eventually a coma or death. It is important for anyone who injects themselves with insulin to know exactly how much they require.

For a few years, insulin has been used to help improve endurance in athletes as well as to build muscles for athletes.

Endurance athletes are helped because insulin helps glucose enter muscle cells. If more glucose enters the cell than is needed then it will stimulate glycogen formation. Glycogen is a kind of "power pack" that can be switched on very quickly.

In an article on insulin, growth hormone and sport, Dr Sonksen from St Thomas' Hospital in London wrote, "Since performance in many events is known to be a function of muscle glycogen stores, bulking up these stores will most probably enhance performance."

Insulin is used in bodybuilding to increase the bulk of muscles. Regular injections of short-acting insulin are combined with a high carbohydrate diet and this has two helpful effects.

Firstly, the insulin works in the same way as it does in endurance athletes - increasing the volume of glycogen and leading to an increase in muscle bulk.

The second effect is that it prevents the breakdown of muscle protein. This means more muscle is made than destroyed, thereby increasing the size of muscles.

But this method of bulking up carries risks. As in the case of the man in Yorkshire, it can lead to a drop in blood-sugar levels, leading to coma or even death.

Some experts also warn that used over the long-term, it could ironically, lead to the development of diabetes, as the body's own ability to produce the hormone falters.

Aside from these problems, most athletes who use the hormone endanger themselves further because they are unsure of the dose that is required. What follows is a game of trial and error - lethal when injecting insulin. Without professional advice this can lead to dangerous practices.

"One [shot] might be good so two might be better and three might be better than that," says Mick Hart. He says he has seen fellow bodybuilders admitted to hospital after taking too much insulin, believing that the bigger the dose the better.

Most people who abuse insulin in sport get hold of it from diabetics but there are reports from "underground" sources that private doctors may well be prescribing insulin to athletes who are not diabetics.

The nightmare scenario according to Hart is if we see criminal gangs importing poor grade insulin from the Far East or Russia. This will cause far more problems than sport faces at present.

What the judges say

The International Olympic Committee (IOC) has very specific guidelines on the taking of insulin. Unsurprisingly, it permits only the treatment of athletes with certified insulin-dependent diabetes and considers it an offence if any other competitors take the substance.

The medical director of the IOC Dr Patrick Schamasch says they can detect the abuse of insulin because injectable insulin differs from natural insulin. Some forms of insulin come from animals such as pigs and some is human insulin but genetically manufactured. "We [at the IOC] are aware that insulin is used in athletes but we are confident that we are able to detect it," he says.

Insulin may appear to be an effective way of boosting performance in a sport where the pressure to be the best is always on. But medics wonder how many more athletes will have to come to harm before its full danger is realised.